Hydraulic equalizing means for vehicle brakes



Sept. 15, 1936. Y J} HULSE -2',054,752

HYDRAULIC EQUALIZ ING MEANS FOR VEHICLE BRAKES Filed July 50, 1955 2 Sheets-Sheet 2 flmsz: H0435 M 'QmMQ I Patented Sept. 15, 1936 PATENT OFFICE j 2,054,752 mzmmom'c noumz'mc MEANS FOR vnmcma BRAKES I James E. Hulsc, Durham, N. 0., assignor of onefourth to Wright: Automatic Tobacco Packing- Machine Company, Durham, N.' 0., a'corporation of West Virginia Application 1111130, 1935, Serial No. 33,892

9 Claims.

The present invention relates tobrakes for automotive vehicles, and more especially to those employing multiple brakes such as four-wheel brakes for the front and ,rear wheels of such vehicles.

One of the primary objects of the present invention is to provide relatively simple, eflicient and inexpensive means for equalizing the brake action applied to the different brakes comprising the brake system.

Another object. is to provide hydraulic 'means for equalizing the brake action applied to the diiferent brakes of a mechanical brake system whereby equal brake action will be produced by each brake.

Another object is to provide hydraulic equaliz ing means for a brake system embodying safety means for insuring brake action in the event the liquid employed in the hydraulic equalizing means should be insuflicientto function because of leakage or other cause.

- A further object of the invention is to provide iiydraulic brake equalizing means which is capable of being readily applied to automotive vehicles and connected to the usual brake pedal and brake rods as a substitute for a part of the equalizing means according to the present invention;

Figure 2 is a, view partly in section on the line 2--2 in Fig. l and partly in elevation and on an enlarged scale, showing the improved hydraulic equalizing means;

, 'Figure 3 is a top plan view of a portion of said brakes.

' Figure 9 is a top plan view of the casing shown in Fig. 8; and

Figures 10 and 11 are sections taken on the lines l0 -|0 and Il-ll respectively in Fig. 8.

Similar parts are designated bythe same reference characters in the different figures.

Hydraulic equalizingmeans according to the present invention is applicable generally to'the brakes of vehicles of various kinds although it is more particularly applicable to the multiple brakes, such for example as the, four-wheel brakes, of automotive vehicles, for the purpose of producing equal brake action by the different brake units comprising the brake system. The preferred embodiment of the invention is shown in the accompanying drawings and will be hereinafter described in detail, but it is tube understood that the invention is not restricted to the precise constructions shown since equivalent, constructions are contemplated and such will be included within the scope of the claims;

In the present instance and as shown in the accompanying drawings, the invention is shown applied to an automobile of conventional construction equipped with four-wheel brakes, l designating the usual automobile frame, 2 and 3 the front and rear axles and 4 and 5 the front and rear wheels, the front wheels being provided respectively with brakes 6 and the rear wheels being provided respectively with brakes I. The

' brakes may be of any conventional or preferred form the details of which form no part of this invention, the brakes being shown for purposes of illustration as provided with cam shafts 8 and 9 having levers l0 and ll thereon for rocking them to expand an internal band, for ex-v ample, into braking engagement with the brake drums fixed to the respective wheels, as is well understood in the art. The levers I 0 for actuating the front wheelv brakes are operated as usual by' a pair of brake rods l2 which are adapted to be pulled rearwardly to set these brakes, andthe actuating levers I I for the brakes of the rear wheels are connected to a pairof brake rods l3 which are adapted to be pulled forwardly to set ll represents the usual brake pedal which may be mounted on a cross shaft l5 supported-in the automobile frame, the brake pedal being operatively connected to the main brake rod l6.

According to the present invention, the front wheel and rear wheel brakes are all operated mechanically by depressing the brake pedal II,

and the brake action transmitted from the brake pedal to the individual brakes is equalized hydraulically by equalizing means 20 which is connected to the brake rods l2 and I3 and the main 'Jrake rod I6 and may be mounted in the automobile frame in place of the rock shaft heretofore used generally for actuating the brake rods. This equalizing means, according to the present invention, comprises a pair of axially alined tubular' or sleeve-like shafts 2| having levers 22 welded or otherwise fixed on their outer ends and extending upwardly therefrom, the brakerods l3 for the rear wheel brakes being pivotally connected to the upper ends of these levers, and a pair of axially alined shafts 23 which are r0- tatably mounted within the shafts 2| and have levers 24 welded or otherwise fixed to their outer ends and extending downwardly therefrom, the brake rods l2 for the front wheel brakes being pivotally connected to these levers. shafts 2| and 23 are individually rotatable relatively to one another and this shaft assembly is mountedvcrosswise in the automobile frame, the sleeve-like shafts 2| for example being rotatably mounted in suitable bearings in the respective side members of the frame.

The equalizing means also comprises a casing 25 which is formed with cylinders 26 which correspond in number to the number of brakes comprising the brake system, four cylinders being shown in the present instance. This casing is formed with a pair of arms 21 into which the inner ends of the sleeve-like shafts 2| are fitted rotatably, and the casing is also formed with an arm 28 into which the inner. ends of the shafts 23 are fitted rotatably, so that the casing is supported to swing or rock about the common axis of the shafts 2| and 23 and said shafts are independently rotatable relatively to the casing. One end of the casing is bolted or otherwise fixed to a sleeve 29 which is rotatably mounted upon one of the sleeve-like shafts 2|, and the sleeve 29 has an arm 30 fixed thereon and extending upwardly therefrom, this arm being pivotally connected to the main brake rod l8 connected to the brake pedal l4, so that the casing will swing upwardly when the brake pedal is pushed forwardly pressed, as in applying the brakes.

Each cylinder 26 of the casing has a piston or plunger 3| fitted to reciprocate therein and a cupped rubber or other suitable sealing cap'32 is provided beneath each piston. The upper end of each piston is formed with arecess 33 in which a connecting rod 34 rests, the upper end of each connecting rod being pivotally connected by a pivot pin 35 to a lever 36. Two of these levers are fixed. to the sleeve-like shafts 2|, as by the keys or pins 31 and the other levers are fixed to the inner ends of the shafts 23 as by the pins or keys 38. The tops of the cylinders in the casing 25 are covered by a cover plate 39 which is secured to the top of the casing, this cover plate having slot-like openings 40 therein through which .the respective connecting rods 34 extend, these openings 40 being narrower than the length of the pivot pins' 35, so that the ends of these pivot pins will bear firmly on the top of the cover plate 39 in the event the pistons move beyond a predetermined extent into their cylinders. In order to seal the cylinders against the entrance of dust, a substantially conical corrugated dust cup of rubber or other suitable 1 flexible material 4| may be attached to each con- The or de-.

The mode of operation of the brake system provided with hydraulic equalizing means as hereinbefore described is as follows:N 'ormally or when the brakes are not applied, the casing 25 will be in its relatively lowered position as shown in Figure 4, the brake pedal I4 being then in its non-actuated position. The pistons 3| in the cylinders 26 in the casing 25 will then occupy positions near the tops of said cylinders. The brakes are' applied by depressing or pushing forwardly the brake pedal l4. Such movement of the brake pedal tensions the main brake rod l6 which, acting on the lever 30, swings the casing 25 fixed thereto, upwardly or into the position shown in Figure 5. Since the spaces in the cylinders be neath the pistons are filled with oil or other liquid and such oil or liquid is confined within the casing, suchliquid will be placed under compression by the upward swing of the casing 25 and will act to transmit motion and power from the casing to the pistons therein to cause the latter to move upwardly with the casing, and since the plstons are connected individually to the respective shafts 2| and 23 by the levers 36,- the motion and power thus imparted to the pistons by the oil or liquid will be transmitted individually to the respective shafts 2| and 23, causing the latter to rotate and thereby actuate the respective brake rods l2 and 3 in directions to;apply the brakes on the front and rear wheels. Since a separate piston and cylinder is provided for each of the two shafts 2| and each of the two shafts 23 and the cylinders are in' intercommunicatio'n through the passageway 42, equal brake applying force will be applied to each one of the four brake rods since the hydraulic pressure will act equally on all of the pistons. Equal brake action will thus be pro- .duced on each of the brakes of the vehicle, not

withstanding that the brakes or their connections may be adjusted unequally, the body of oil or liquid acting in common upon all of the pistons functioning as an equalizing medium. For example, if one or more of the brakes or their connections are not properly adjusted to produce effective brake action on the respective wheel or wheels, the pistons connected to the other brakes will relatively move downwardly in their cylinders,

as shown in Figure 5, thus forcing oil or liquidfrom these cylinders into the cylinders for the pistons connected to the brakes which are inefllciently adjusted, thereby insuring the transmission of power equally to all of the brakes to effect equalized brake action thereon.

In the event the casing contains an insumcient amount of oil or liquid to transmit the required movement between the casing and the pistons to set the brakes, as might occur from leakage of oil from the casing, the upward swing of the casing 25 under the action of the brake pedal in applying the brakes will bring the cover plate 39 into direct mechanical engagement 'with the pivot pins 35 connected to the levers 38,. and the movement of the brake pedal will then be transmitted directly and mechanically tdthe brake rods and effect oil or other equalizing liquid in the cylinders.

By constructing the brake rod'actuating shafts, cylinder casing and pistons andactuating levers as herein shown and described, the hydraulic equalizing means provided'by the present'invem.

arose-ma tion may he readily and inexpensively applied to automobiles in place of the usual rock shafts for actuating the brake rods, without requiring any alteration in the rest of the hralre system, which may he of any usual or conventional construction. line construction of the equalizing means is also such as to avoid the necessity of using pining for the equalizing liquid, which is subject to leakage and breakage and otherwise objectionable.

The present invention enahles a brake system to he en vl'hich comprises mechanicolly actuated hraires at the wheels of the vehicle the action cl ch equalized. hydraulically, without the clls= employing hrakeoctuat ing' cylinders st the wheels cool extending piping thereto as in so-csllecl hydraulic Torches as hereto- I tore usecl or prose-seal, it thus possessing the'ad Til oi axially alinecl independently rotatable ele ii nts connected respectively to said. hralre acclinics" mernher con for rotation tuatingt rs, to

there y elements hav ing an row intercommunicatino eylin e plurality oi pistons corinecterl incl- .r spective elements oneratti e i in the resp ctive cylinders s c con non to pressure enrolled. to the flute "l fluid-containing;

2. ism icc vehicles comprising ti er and a plurality of hralre octuatino one operative thereby, o. pliuelity of inecl lnalenenclently rot table elicits conoective y to sale brake actuating locu co log mifiil'lbiif mounted to re tale about said shafts c ol connected en er tin inherone ion thereby, and i 'o to'ns individually the ts and subject in common pressure a so. to the contained in oaicl lol ccntainlnc member.

3. in cralre mechanism for vehicles compris ins; an operating anti plurality of hralse actuating members operative thereby, o'plurality azzlslly sliced ll. enenclently rotatable shafts connecterl respectively to saiol lorolre actuating a casino rotatahly mounted on saitl shafts to rotate about the axis thereof anti connectecl to ssiol operating member for operation therehy, sai cosinoeontainino fluid, a plurality oi pistons movahly fitted into solo casing and. suhiect in common to the pressure or the fluid therein, and means operativeiy connectiny, said pistons individually to the respective shai'ts.

i in maize meclioroisin for vehicles comm-icing memher one a olurollty or hrolr'e actuating members operative thereby, a 'plurolity of serially olineol independently rototohle connected respectively to sairl loreilae actuating members, a casino rotatably mounted on shafts to rotate shoot the thereof and corn necteci to said operating member ior operation thereby, said cosine having as plurality of intercoininunicating cylinders therein to contain is hold, a plurality of pistons mounteil to recioro- 1 ually to the respective loralre actuating members, it

a casing having portions forming hearings rotatahly fitted on said pairs of shafts and com ,nected to said operating member for operation thereby, said casing containing a fluid, plurollty of pistons reciprocahle in saicl casing and subject 1 in common to pressure of the fluid therein, url means individually and independently comic-act inc sale. pistons to the respective shafts.

(i. In brake mechanistic for vehicles. cgmpiy sir an operating member anal e, plurality of bra actuating mernhers operative thereby, p axially aiineel shafts and another pair of i alineo. shafts sleeved over the first-men shafts, meansfcr connecting" soicl shafts mo uaily to the respective wake-actuating memh to, it a casing" having portions forming hearings rota? ably fltterl on said pairs of shafts and connecteo to said operating for operation the eby, said casing containing a a plurality oi tons reciprocable in casing and. suliie J A common to pressure of the therein, and: plurality of levers ilxecl individually to the r c tive shafts and operatively connected inolivi to the respective pistons.

7. Sin hralze mechanism for vehicles compels on operating mernher plurality of limit tuating members operative thereby, a pair or 1 iclly aiinecl another of axial alinerl shafts sleevecl over flrst rnentionerl shafts, mean for connecting saicl shafts virtually. to the respective hralre actuating hers, o casing having s cecal hogs thereon lo hearings rotatahly fitted to the inner encls pairs of shafts and connected to saici o n'iemloer for operation thereby, casirl taming an equalizing llouiri, nl'orolity of individual to the re reciprocote inclivclually ill casing subject in common to pressure of the therein, and levers illzeil inner emls oi she-its between said the casino and moons i'cr actuating" them individually ,iroo respective pistom.

t. In brake mechanism for vehicles com an operating: memher a plurality oi r Ell aiinecl shafts sleeverl over the first-eneutlomri shafts-means for connecting said shatts inc" ually to the respective h rlikeacmating men a casing having a row of cylinders formed the: and a passageway connecting them, said casing containing an equalizing liquid, means rotatably mounting the casino on salrl shafts tor rota" about the axis thereof, means connecting one 55 casing to saiol operating member for operation thereby, pistons reciprocahle individually in cylinders hut-subject in common to pressure or the liquid therein,- one a row of levers fixed to the reogoectiveishalts "and having means for ac tuoting theni in zllvloluclly from the respective pistons.

9., In brake mechsnism for vehicles comprising an operating member and a plurality of brake actuating members operative thereby, a pat-r or axially alined shafts and another pair of axially alined shafts sleeved over the first-mentioned shafts, means for connecting said shafts individually to the respectivebrake-actuating members, a casing having a row of cylinders termed therein and a passageway connecting them, said casing containing an equalizing liquid, means'rotatably mounting the casing on said shafts for rotation about the axis thereof, means connecting the 10 casing to said operating member for operation I thereby, pistons reciprocable individually in said cylinders but subject in common to pressure of the liquid therein, a row of levers fixed to the respective shafts and having means for actuating them individually from the respective pistons,

and a cover plate on the casing for the cylinders therein engageable with portions on said levers to actuate them in the absence 0! liquid in the casing.

JALmS E. ,HULSE. 

